Silmaril (foaled March 31, 2001 in Maryland) is an American thoroughbred mare racehorse.
She was out of the mare, Kattebuck, whose sire was the 1985 United States Horse of the Year, Spend A Buck.
Silmaril is probably best known for defeating the Eclipse award winning filly, Ashado twice, once in the grade two Pimlico Breeders' Cup Distaff Handicap (now called Allaire duPont Distaff Stakes) in 2005 and in the What A Summer Stakes in 2007.
Silmaril was also a very popular mare at Laurel Park Racecourse and throughout Maryland.
Tolkien tales, Silmaril is one of only five Maryland-bred mares to ever reach the million dollar mark in total earnings on the racetrack.